Starter and circuit for electric discharge device



Aprll 16, 1963 J; H. RUBENSTEIN 34 9 STARTER AND cmcun FOR ELECTRICDISCHARGE DEVICE Filed April 24; 1958 I i 1 I l l l C I V5 g I 3 X i i33 L J I 7 //MAGNETIZING L I FORCE F162 F1C5.l

.=////////////////////////= if; 45 x 4| INVENTOR. JACOB l-LRUBENSTEINBYWIO-W AGENT United States Patent 3,086,141 STARTER AND CIRCUIT FORELECTRIC DISCHARGE DEVICE Jacob H. Rubenstein, 101 Shirley Road,Syracuse, N.Y. Filed Apr. 24, 1958, Ser. No. 730,720 12 Claims. (Cl.315--100) This invention relates to an improved starter and startingcircuit for :a gaseous electric discharge device having thermionicelectrodes, such as a hot cathode type of fluorescent lamp, or the like,and more particularly to a starter which will positively ignite such adevice the first time that it causes a starting voltage to be impressedacross it. While the following description refers to a fluorescent lamp,it will be understood that it may be equally applicable to analogouselectric discharge devices.

It is well known that the life of a fluorescent lamp is inverselyproportional to the number of times that starting voltage is impressedacross the lamp whether the lamp actually ignites or not. In practicallyall the starters of the prior'art ignition of the lamp did not occuruntil starting voltage had been impressed across the lamp a few times,this procedure materially reducing lamp life and causing objectionableblinking during this starting process. In addition to the foregoingobjectionable blinking, starters of the prior art permitted afluorescent tube to blink objectionably after it wore out. It is withthe overcoming of the foregoing shortcomings of the fluorescent lampstarters of the prior art that this invention is concerned.

It is therefore the principal object of this invention to provide afluorescent lamp starter which will prolong the life of :a fluorescentlamp by positively igniting the lamp upon the initial impressing ofstarting voltage across it.

A further object of this invention is to provide an im proved starterwhich prevents blinking of a fluorescent lamp not only upon starting butalso when the lamp is worn out, this in turn preventing a reduction inthe life of the starter associated therewith and eliminating theannoyance caused by the blinking of a fluorescent lamp.

Another object of this invention is to provide a starter which willoperate over a wide voltage range so that it will positively ignite afluorescent lamp even when the line voltage varies abnormally. Otherobjects and attendant advantages of the present invention will readilybe perceived hereafter.

The starter of the present invention achieves the foregoing objects bypositively initiating the starting voltage close to the peak value ofthe current cycle, thereby caus ing a maximum voltage kick. to beimpressed across the fluorescent lamp. This occurs after a predeterminedlamp-filament preheat time has elapsed. This procedure causes thefluorescent lamp to positively ignite upon the initial impressing ofstarting voltage across it.

The present invention relates to a starter and starting circuit forpositively igniting a fluorescent lamp .upon the initial application ofstarting voltage across the electrodes thereof comprising a source ofelectric current, a ballast reactor coupled to said lamp, means forpreheating said electrodes for 13. predetermined period, and means forcausing said ballast reactor to provide a starting voltage across saidlamp after said preheat period has elapsed to positively ignite saidlamp the first time starting voltage is impressed across saidelectrodes. The obtaining of the starting voltage which will positivelyignite the lamp is due to the use of a magnetic relay having a core andarmature of magnetic material of low coercive force or low retentivity.This material causes the starting voltage to be impressed atsubstantially the peak value of the current cycle so that the voltageproduced by the ballast reactor is at a maximum. The present inventionwill be more fully understood when the following portions of thespecification are read in conjunction with the accompanying drawings,wherein:

FIGURE 1 is a schematic wiring diagram of a fluorescent tube circuitincluding the starter of the present invention, the portions shown inphantom deepicting the positions of starter elements after the initialimpressing of starting voltage across the fluorescent lamp;

FIGURE 2 depicts a hysteresis loop of the low coercive force corematerial of the relay used in the starter, and, in broken lines, thehysteresis loop for conventional magnetic material; and

FIGURES 3 and 4 depict the actual construction of my improved starter,with certain parts omitted in the interest of clarity, FIGURE 4 being aview taken from the right of FIGURE 3.

Reference is now made to FIGURE 1 which shows a fluorescent lamp 10having electrodes 11 and 12, which may consist of any conventionalthermionic material. One side of electrode 11 is coupled through aconventional ballast reactor 13 to line L and one side of electrode 12is coupled to line L through power switch 14.

The improved starter 15 of the present invention is coupled across theother sides of electrodes 11 and 12 by means of conductors 16 and 17,respectively. Starter 15 is preferably enclosed in a conventionalstarter case 39 (FIGURE 3) so that it may be interchanged withconventional starters now in use as the latter wear out. Coupled acrossleads 16 and 17 are a relay 18 having a core 19 of low magneticretentive force (low coercive force) material and a current limitingresistor 20. Relay winding 21 and resistor 20 are coupled in series byconductor 22.

Coupled across leads 16 and 17 by means of leads 23 and 24,respectively, is the preheating circuit for the filaments of lamp 10.During the preheat time which immediately follows the closing of switch14, current flow is from L through switch 14, filament 12, lead 17, lead24, lead 25, low coercive force relay armature 26, contact point 27 onthe relay armature, contact point 28 (which is mounted on bimetallic arm29), resistance heating coil 30, lead 23, lead 16, filament 11, landballast reactor 13 to complete the circuit to L As is well known, theflow of current-through the filaments 11 and 12 causes them to heat up.

The parameters of the entire starter circuit are such that noappreciable current will flow through relay coil 18 during the preheattime because the above-described preheat circuit serves as a shunt.

The passage of current through resistance heater 30 will causebimetallic arm 29 to be heated. The characteristics of bimetallic arm 29and heater 30 may be chosen to give any length of preheat time requiredfor any particular lamp. As arm 29 heats up, it will tend to deflectupwardly, thus tending to separate contacts 27 and 28. When the desiredpreheat time has elapsed, the point is reached where contacts 27 and 28will start to separate and the shunting circuit across relay coil 21will terminate because the spreading apart of contact points orterminals 27 and 28 will in effect initially provide a, high resistanceair gap, thus starting to overcome the shunting characteristic of thepreheat circuit. As contacts 27 and 28 start spreading apart because ofthe upward movement of bimetallic arm 29, higher current will startflowing through relay coil 21. Substantially at the instant when thecurrent cycle reaches its peak value through coil 21, suflicientmagnetization will be induced in low-coercive-force core 19 topositively pull down armature 26 (which is also made of low retentiveforce magnetic material) to its dotted line position, thus opening thecontact points at substantially the peak value of the current cycle.

I believe the reason that contact points 27 and 28 will open very closeto the peak of the current cycle is because the high permeability-lowretentivity material, which is used for the core and armature of theA.C. relay, has the property of having its induced magnetic flux closelyfollow the phase and wave form of the magnetizing force (which isproportional to the current through the relay coil). Furthermore, -forlow values of magnetizing force, such as used in the relay of thepresent fluorescent lamp starter, the magnetic flux is proportional tothe magnetizing force. Also, due to the low retentivity of the materialin the core, there will be -a well defined magnetic peak pull on thearmature of the relay. The foregoing characteristics will readily beappreciated from FIGURE 2 wherein curve 33 depicts the hysteresis loopof the low retentivity material which I utilize whereas curve 34represents the hysteresis loop of a conventional laminated corematerial.

Armature biasing spring 42 is adjusted so that the armature downwardmovement responds only to the peak magnetic pull, and, as it has beenpointed out above, this peak magnetic value occurs substantiallysimultaneously, in time, with the peak of the current cycle. Therefore,the contact points 27 and 23 open substantially at the peak of thecurrent cycle.

When the preheating circuit is broken in the above described manner sothat it no longer provides a shunt across electrodes 11 and 12, thestored magnetic energy in ballast reactor 13 will produce an inductivekick (or starting voltage) across electrodes 11 and 12 to positivelyignite the lamp 10. This positive ignition is due to the high value ofthe transient voltages set upacross the lamp when the current isinterrupted at substantially peak value, in the above-described manner.Insofar as pertinent, the peak value of the current cycle is any valuesufficient to cause ballast reactor 13 to produce an inductive kickwhich will cause positive ignition, this value usually being where thecurrent is at least approximately 90% of its maximum value.

Once the lamp 10 is positively ignited in the foregoing manner, currentwill continue to flow across leads 16 and 17 through relay coil 21, lead22, and current limiting resistor 20. This maintains relay 18 in anenergized condition and keeps armature 26 in its dotted-line position sothat contact points 27 and 28 remain separated. This separation preventsblinking of a worn out lamp, this blinking ordinarily occurring with aconventional starter (which does not have this feature) as it attemptsto ignite a worn out lamp which is incapable of being fully ignited.

Capacitor 31 is coupled between lead 24 and one end of bimetallic arm29. This capacitor has a high capacitative reactance so that only aminute amount of current will flow through arm 29 and resistance heater30 when the relay 18 is energized. Since this minute current is muchlower than that previously flowing through resistance heater 30, thelatter will cool to normal ambient temperature and thus assume itsstarting position so that when switch 14 is opened, armature 26 (whichis spring biased upwardly) will assume its solid line position to placecontacts 27 and 28 in engagement so that the starter componentsimmediately assume the necessary position for a subsequent startingoperation.

A low coercive force material which I have used successfully is known bythe term Allegheny Mumetal and is a commercial product of AlleghenyLudlum Steel Corporation. The typical chemical composition of thismaterial is 77.2% nickel, 4.8% copper, 1.5% chromium and 14.9% iron.

In FIGURES 3 and 4 is shown a preferred construction of my improvedstarter illustrating the preferred orientation of parts, the wiringconnections of FIGURE 1 having been omitted for the sake of clarity. Thesame numerals on these figures which appear in FIGURE 1 depict the sameelements described above relative to FIGURE 1, and it is believed that adetailed repetition of these numerals is superfluous. In addition to thecomponents set forth in FIGURE 1, FIGURES 3 and 4 disclose a circulardielectric disc or base 36 having terminals 37 and 38 mounted thereonwhich are adapted to be received in a mating starter socket (not shown).Mounted on disc 36 is a cylindrical shell or housing 39 which, incombination with disc 36, encloses the starter. The relay core 19 ismounted on an L-shaped bracket 40, and positioned in the space below thehorizontal arm of the bracket are capacitor 31 and resistor 21}. Aninverted U-shaped yoke 41 has its depending legs fastened to relay coil21 in any suitable manner. Extending upwardly from the horizontal leg ofbracket 40 is a piece of spring metal 42 (such as piano wire) to whichis fastened armature 26 which is made of the low coercive force metaldescribed above. Attached to yoke 41 by means of support '43 isbimetallic arm 29. Support 43 has an end portion 44 to limit the upwardmovement of armature 26. The free end of bimetallic arm 29 has fastenedthereto an inverted U-shaped bracket 45, the depending legs of whichstraddle the armature 26 to prevent the latter from undesirable lateraldisplacement. Upon downward movement of bimetallic arm 29, the ends ofthe depending legs of U-shaped bracket 45 contact relay coil 18 to limitdownward movement of arm 29 under extremely cold ambient conditions.

It can be seen from the foregoing description that a fluorescent lampstarter has been disclosed which positively ignites a fluorescent lampupon the initial application of starting voltage across the terminalsthereof, thus materially prolonging the life of the lamp and eliminatingobjectionable blinking during starting.

It must be appreciated, however, that the positive starting of the lampWill occur only while the lamp is within its normal life span, i.e.,before it becomes worn out. When the lamp is bad, ignition will notoccur, thus indicating that the lamp should be replaced. However, sincearmature 26 remains in its dotted line position after a starting attempthas been completed, there will be no objectionable blinking of theworn-out lamp because of the elimination of the continued startingattempts which cause the blinking of the worn-out lamp.

As noted above, the starter of the present invention also positivelyignites a fluorescent lamp at low values of line voltage because italways causes the ballast reactor to produce a maximum inductive kickinasmuch as the latter is produced at substantially the peak of thecurrent cycle.

While I have described a preferred embodiment of my invention, I desireit to be understood that it is not limited thereto but may otherwise beembodied within the scope of the following claims:

I claim:

1. A starting circuit for positively starting a gaseous electricdischarge device a predetermined time after the circuit is energizedcomprising a source of electric current, switch means for coupling saiddevice to said source of current, a ballast reactor coupled to saiddevice, a time delay circuit means for permitting preheating current toflow through the electrodes of said device after the closing of saidswitch means, and means for substantially simultaneously terminatingsaid preheating and causing said ballast reactor to always produce itsinitial voltage discharge across the electrodes of said device atsubstantially the peak value of the current cycle to positively startsaid device upon the initial application of voltage across saidelectrodes by said ballast reactor.

2. A starting circuit for a gaseous electric discharge device havingelectrodes adapted to be energized from a source of electric current bythe use of a switch for coupling said electrodes across said source ofcurrent, said starting circuit including a ballast reactor coupled tosaid device, a time delay circuit adapted to permit preheating currentto flow through said electrodes for a predetermined time after saidswitch is actuated, and circuit means shunted by said time delay circuitduring said predetermined time for positively causing said predeterminedpreheating time to terminate and causing said ballast reactor topositively produce its initial voltage discharge across said electrodesat substantially the peak value of a current cycle to thereby positivelystart said device upon the initial application of ballast reactorproduced voltage across said electrodes.

3. A starter for a circuit having a ballast reactor and a gaseouselectric discharge device having a plurality of electrodes including atleast one thermionic electrode therein comprising preheat means forpermitting current to flow through said thenmionic electrode for apreheating period, and means for causing said ballast reactor to alwaysimpress its first voltage discharge across the electrodes of saiddischarge device after the termination of said preheat period and atsubstantially the peak value of a current cycle whereby said electricdischarge device will always start the first time that said ballastreactor impresses a voltage across said device.

4. A starter for an electric discharge device having at least onethermionic electrode in a circuit with a ballast reactor comprisingmeans for providing a single preheating period for said electrode, andmeans for causing said ballast reactor to impress a starting voltageacross said device only once at substantially the peak of a current.cycle after said preheating period to thereby either cause starting ofsaid discharge device with a single ballastreactor produced voltage ifit is capable of functioning or prevent blinking of said dischargedevice if it is incapable of functioning by preventing additionalstarting attempts.

5. A starter for an electric discharge device having at least onethermionic electrode, said starter adapted to be used in a circuit witha ballast reactor and a first switch for coupling said device to asource of electric current, said starter comprising a second switchhaving first and second contacts, a thermostatic element adapted to movesaid first contact, a relay having a winding and a core and an armature,said armature adapted to move said second contact, heating meansassociated with said thermostatic element, first circuit means operativeafter the closing of said first switch for permitting current to [flowthrough said ballast reactor and thermionic electrode and second switchand heating means to thereby preheat said thermionic electrode, saidfirst and second contacts tending to separate as a result of the efiectof the heat produced by said heating means causing said thermostaticelement to deflect, and second circuit means coupling said relay Windingto said source of current, said second circuit means permittingsufiicient current to flow through said relay winding as said first andsecond contacts tend to separate to cause said armature to deflect andsaid second switch to positively open at substantially the peak value ofa current cycle to thereby terminate preheating of said electrode anddisrupt the flow of current through said ballast reactor atsubstantially the peak value of said current cycle whereby the voltagedischarge produced by said ballast reactor at said peak value of saidcurrent cycle will start said electric discharge device.

6. In combination in an electric circuit having a source of alternatingcurrent, a device relative to which it is critical that a switchingaction be performed at a predetermined portion of a current cycle, firstselectively actuable switch means for coupling said device to saidsource of current, circuit means including second switch means forpermitting current to flow to said device after the actuation of saidfirst switch means, said second switch means including a relay armatureassociated therewith, and electromagnetic relay means including saidarmature and responsive to a variation in the flow of current throughsaid electromagnetic relay means for eifecting a deflection of saidarmature and thereby actuating said second switch means at saidpredetermined portion of said current cycle.

7. A starter for an electric discharge device having at least onethermionic electrode for use in combination with a circuit having aballast reactor and a source of alternating electric current and switchmeans for coupling said electric discharge device to said source ofcurrent, said starter comprising circuit means for permitting preheatingcurrent to flow through said thermionic electrode after the closing ofsaid switch means, and means for causing said ballast reactor to alwaysimpress a starting voltage across said device only once and atsubstantially the peak of a current cycle after said preheating currenthas flowed through said thermionic electrode for a predetermined periodafter the closing of said switch means to thereby either cause startingof said discharge device while subjecting it solely to a single ballastreactor produced voltage discharge if it is capable of functioning,without causing blinking of said discharge device due to additionalstarting attempts producing additional ballast reactor produced voltagedischarges if it is incapable of functioning, and means for resettingsaid circuit means in response to the opening of said switch means tothereby prepare said circuit means for a repetition of the flow of saidpreheating current through said thermionic electrode and the singleimpressing of said starting voltage in response to a subsequent closingof said switch means.

8. A starter for an electric discharge device comprising a base, ahousing mounted on said base, a plurality of terminals adapted to becoupled to a source of current, a relay mounted within said housing,said relay having a core and a winding and an armature, first circuitmeans coupling said winding across said terminals, a switch having apair of contacts, one of said contacts being mounted for movement bysaid armature, second circuit means coupling said switch across saidwinding, means for causing said first and second contacts to startseparating as a result of the passage of current through said secondcircuit means, said first circuit means permitting sufiicient current toflow through said winding as said contacts tend to separate to causesaid armature to be deflected, and means operatively associated withsaid relay for causing said switch to always produce its initial openingat substantially the peak value of a current cycle.

9. A starter for an electric discharge device having a pair ofelectrodes including at least one thermionic electrode, said starteradapted to be used in a circuit with a ballast reactor and a firstswitch for coupling said device to a source oi? electric current, saidstarter comprising first circuit means including a second switch havingfirst and second contacts, a thermostatic element including heatingmeans adapted to move said first contact, a relay having a winding and acore and an armature, said first circuit means being coupled across saidelectrodes and operative after the closing of said first switch forpermitting current to fiow through said ballast reactor and thermionicelectrode and second switch and heating means to thereby permit currentflow to preheat said thermionic electrode, said first and secondcontacts tending to separate as a result of the effect of heat producedby said heating means causing said thermostatic element to deflect, andsecond circuit means coupling said relay winding across said secondswitch, said second circuit means permitting increased current to flowthrough said relay winding as said first and second contacts tend toseparate, and said relay including means for causing said armature to bedeflected and said second switch to positively open at substantially thepeak value of a current cycle to thereby terminate preheating of saidelectrode and disrupt the flow of current through said ballast reactorat substantially the peak value of said current cycle whereby theinitial voltage discharge produced by said ballast reactor occurs atsaid peak value of said current cycle to thereby start said electricdischarge device upon the initial impressing of ballast reactor producedvoltage across said electrodes.

10. A starter as set forth in claim 9 wherein said means included insaid relay comprise a low coercive force material.

11. A starting circuit as set forth in claim 2 wherein said time delaycircuit means is connected across said electrodes and includes a switchactuated by the armature of a relay, said armature being of low coerciveforce material.

.12. A starting circuit as set forth in claim 11 wherein said relayincludes a core of low coercive force material for deflecting saidarmature to break said time delay circuit means, said core having awinding connected across said electrodes.

References Cited in the file of this patent UNITED STATES PATENTS2,155,816 Babb Apr. 25, 1939 2,181,294 Biggs Nov. 28, 1939 2,341,520Babb Feb. 15, 1944 2,378,222 Inman June 12, 1945 FOREIGN PATENTS 530,098Great Britain Dec. 4, 1941)

1. A STARTING CIRCUIT FOR POSITIVELY STARTING A GASEOUS ELECTRICDISCHARGE DEVICE A PREDETERMINED TIME AFTER THE CIRCUIT IS ENERGIZEDCOMPRISING A SOURCE OF ELECTRIC CURRENT, SWITCH MEANS FOR COUPLING SAIDDEVICE TO SAID SOURCE OF CURRENT, A BALLAST REACTOR COUPLED TO SAIDDEVICE, A TIME DELAY CIRCUIT MEANS FOR PERMITTING PREHEATING CURRENT TOFLOW THROUGH THE ELECTRODES OF SAID DEVICE AFTER THE CLOSING OF SAIDSWITCH MEANS, AND MEANS FOR SUBSTANTIALLY SIMULTANEOUSLY TERMINATINGSAID PREHEATING AND CAUSING SAID BALLAST REACTOR TO ALWAYS PRODUCE ITSINITIAL VOLTAGE DISCHARGE ACROSS THE ELECTRODES OF SAID DEVICE ATSUBSTANTIALLY THE PEAK VALUE OF THE CURRENT CYCLE TO POSITIVELY STARTSAID DEVICE UPON THE INITIAL APPLICATION OF VOLTAGE ACROSS SAIDELECTRODES BY SAID BALLAST REACTOR.